When applying ViTs in ReID tasks, a straightforward way is to introduce IBNNet-a block into the convolution stem. Following the original design of IBNNet-a, we propose IBN-based convolution stem (ICS), as shown in Figure REF , by applying BN for half of the channels and IN for the other half after shallow convolution layers, and applying only BN layers after deep convolution layers. In this paper, we choose to apply IN after the first two convolution layers. Another variant worth consideration but may slightly reduce performance is to only apply IN after the first convolution layer. The kernel sizes, channels and strides of the convolution stem are kept the same as in [1]}. Hereinafter, we denote ViT with patchify stem, convolution stem, and ICS as ViT, ViT\(_C\)  and ViT\(_I\) , respectively
